Apparatus for circulating and distributing flotation pulp



Nov. 19, 1929.

APPARATUS FOR CIRCULATING AND DISTRIBUTING FLOTATION PULP Filed Nov. 9, 1927 4 Sheets-Sheet 1 l I N Q Jnuentoz M4. 'F 7GEZGIQEN,

w. FAGERGREN 1,736,073

Nov. 19, 1929. w. FAGERGREN APPARATUS FOR CIRCULATIN G AND DISTRIBUTING FLOTATION PULP Filed Nov. 9, 1927 4 Sheets-Sheet 2 .w W m W 46EEGZEM Nov. 19, 1929. w. FAGERGREN' 1,736,073

APPARATUS FOR CIRCULATING AND DISTRIBUTING FLOTATION PULP Filed Nov. 9, 1927 4 Sheets-Sheet 5 W. FAGERGREN' Nov. 19, 192 9.

APPARATUS FOR CIRCULATING AND DISTRIBUTING FLOTATION PULP 4 Sheets-Sheet 4 Filed Nov. 9, 1927 Patented Nov. 19, 1929 WILLIAM FAGERGREN, OI SALT LAKE CI'li, UTAH, ASSIGNOR "1'0 UNIVERSAL ,ENGI- NEERING COMPANY, OF SALT LAKE CITY, UTAH, A CORPORATION OF UTAH arrana'rns For. GIBGULA'IING AND msrnnaurme rtorn'rrolv PULP g ucauonmea November 9, 1927. Serial no. 232,164.

This invention relates to an apparatus for circulating and distributing pul in the practice of the flotation process, an its principal ob]ects are:

First. To provide means' for efliciently subjecting flotation pulp again and again to the action of the impeller 1n the barrel-type of flotation machines, and more particularly in the flotation machines forming the subj ects. 1 ofthe U. S. Patent No. 1,361,342 granted to .lrving R. Margetts and myself, and my pending ap lication for patent, filed November 9, 1927, erial No. 232,165. 1

Second. To prevent the pulp from short circuiting in passing through the flotation machine a Third. To efiiciently circulate the pulp through an individual machine and to selec-' tively distribute the same for further treatment successively through other individual machines.

In the practice of the flotation rogess for extractin the values from metalli erous ores, it is usua y' advantageous to efi'ect the treat-- ment in stages, these stages being carried out in different machines. That is to say, th pulp is passed through the first machine and a certain proportion of the values extracted" a g the tailings from this machine are then passed so through a second machine, the tailings from the second through a third, and so on, until.

substantially the maximum attainable separation has been reached. A clean separation of the mineral from its gangue can seldom. or never be attained in one machine or in one stage.

By means of the present invention, the pulp is circulated through each machine and suballowed to pass on to the next machine. This thorough aeration is accomplished by feeding orprojecting the pulp into each machine, substantiall at right angles to the elements of the impe 'ler and referably tangentto its periphery, Thus, t e feed strikesthe impeller transversely, so that it is carried round and round before reaching the opposite end of the impeller. By

machine near one end of theimpeller, and

9 maintaining a constant feed, the pulp will peller, compelling the v at the top of the machine.

' sible to -achieve a combination capable 0 exhaving the inlet to the be forced gradually along the longitudinal dimension of the impeller, and theoretically, will travel in a path having substantially-the form of a helix. The pitch of the helix is determined by'the relation of the amount of feed to thespeed of rotation of the impeller. In general, the smallerthe feed for a certain speed of rotation of the impeller, the smaller will be the pitch, and. the greater the feed, the greater willbe the pitch. Thus, by regulating the circulation of the pulp in this machine, a high degree of extraction is obtained. The tailings outlet of the machine is located in the end of'the housingand above the.im-. pulp to take a circuitous pat-h from the pulp inlet to the tailings outlet, so that While the pulp is in transit, the bubbled aeration has the fullest oportumty of picking up the values and carrylng them off a By grouping the flotation machines, and arrangin the individual machines so that the .tailings rom any machine can be carried.

to any of the successive machines, it is ostracting to a maximum degree, thevalues of any ore, no matter ho complex.

Thefeatures of this invention for which the protection of Letters Patent is desired, are collectively grouped in the claims coneluding this specification.

. In the drawings, which illustrate merely one embodiment of this invention,

Fig. 1 represents a longitudlnal section through a group of barrel-type flotation machines equipped with this invention, the section being taken in the plane indicated by p line 1-1 in Fig. 3; jected to aerat on agam and agaln before it is motion in the agitation chamber 26 which is defined by the walls of the housing. A1139 is a shield which extends lengthwise of the impeller just above its peripheral elements 5 35, and from end to end of the housing. One edge of the shield is spaced apart from the "*rgwall 21 by only a very small amount, possibly %'of an inch. The other or cutting edge, of the shield, is spaced apart from the oppositewall a much greater distance, though still restaicted, as indicated at 41. At 46 is an ad iustable baflie or valve movably supported, for instance on pivots, whose common axis extends lengthwise of the bafiie, and located contiguous or in proximity to the saidno po site wall, by means of which the rate 0 circulation, and the amount of pul operated upon, may be controlled. In eifiicting this control, the bafie, which naturally has a piv- -0ted or pivotal edge and a free edge, will have the freeedge movable towards or away from the shield and its cutting edge. The baflie may be actuated by a suitable mechanism, such for instance, as the rod and hand wheel 5 shown in the present drawing, and fully described in application 232,165. By means of the actuating mechanism, the free edge of the :bafile may be seated substantially in contact with the shield adjacent its cutting edge.

The pulp enters the chamber 26 through the opening 27 which is preferably inclined downwardly so as to conduct the incoming stream of pulp preferably tangent to the impeller. When-the impeller is rotated, circuazs lar motion is imparted to the pulp, which then follows approximately the path indicated by the arrows. The pulp is drawn around the impeller repeatedly, following virtually a helical course, as indicated in Figs. 5 and 6, until finall it follows the airrow28 and flows out oft e agitation chamber through the outlet 59. The theoretical pitch of the helices ma be calculated from the quantity of the fee and the speed ofrotation. The outlet 59 opens into the .part 291 of launder 29, where it may encounter the variable weir 30 and flow over into the part 292 of the launder. From here, when the regulatin gate 40-1 is closed, the tailings from t e first machine flow down through the conductors 31-1 and 321 as well as through the various connecting fittings," through the openin 27-- 1 into the agitating chamber 26-10 the second ma- 5 chine. Here the tailings go through an agitating and, aerating cycle similar to the one previously described. 8

' Subsequently the tailings from the second machine go to the third, and so on from mao chineto machine.

' In Fig. 5, the course traveled by the'pulp can be seen at a glance. The heavy lines indicate diagrammatically the course, while the lines 20, 20'-1, 20-2, and so on indicate the impellers around which the course leads.

If desired, the course may be made to omit any machine by simply placing stoppers or plugs (not shown) in the intakes such as 31, and in the outlets, such as 59, of the particular machine or machines not wanted in the course. At the same time the correspondinggate l0 and corresponding weir 30 in the launder should be removed. In Fig. 6, the second machine is indicated at out out of the course.

The initial pulp begins its course at 34:, the tailings from one machine becoming the feed or fractional pulp for a succeeding machine or machines.

The novelty of the present invention consists in providing means for compelling the liquid or semi-liquid under treatment, to follow a circuitous, substantially regulable helical course from the inlet to the'outlet of individual flotationvm'achines of the barrel type, and from one machine to another in a plural ity of machines arranged in series or batteries,

for the fractional, progressive treatment of the material operated upon.

The travel of the incoming stream of pulp transverse and substantially tangent to the impeller, compels the pulp to follow the in fluence of the impeller and thus to be drawn round and round as described, and prevents the pulp short circuiting from the pulp inlet to the tailings outlet. By short circuiting I mean, to travel in a substantially direct path from the inlet to the outlet. This advantage will become more manifest b referring to. Patent No. 1,361,342 previous y mentioned herein, where the inlet to the machine directs the stream of incoming pulp longitus dinall alon the peripheral elements of the impel er. or this reason, a considerable-- percentage of the pulp reaches the tailin s 5 outlet in too direct a manner, and so the pn p is not subjected to as thorough an aeration as in the presentapparatus.

The present drawings show the flotation machine described in my co-pending appli no cation for patent, Serial Number 232,165, also previously mentioned herein, incorporated with the present apparatus.

I do not assert that the initial stream of ulp entering the present apparatus retains m its identity as regards the individual particles of matter making up the helical stream? at any particular moment, but rather, that every particle is compelled to follow approximately the helical course outlined.

While a specific embodiment of this invention is herein shown and described, it is to be clearlyunderstood that all the detailed parts thereof may or may not be shown in the preferred forms, and further,that the preferred formsmay be varied from time to time, as thedevelopment of this invention and the' arts to which it appertains, advance.

- Therefore, that which forms an essential and.

characteristic part offthls invention, will-" be readily discernible from the claims in which its spirit is generalized.

Having fully described my invention, what I claim is: 4

1. An apparatus for circulating flotation pulp comprising a rotatable barrel-type impeller, a housing for said impeller, a shield over said impeller, said shield having a cutting edge spaced apart from a wallof said housing, a baflie pivoted lengthwise along one edge thereof so the free baflle edge shall be movable towards or away from said cutting edge, an inlet for pulp directed substantially tangential and at right angles to the peripheral elements of the said impeller, and an outlet for tailings above said impeller.

2'. An apparatus for circulating flotation pulp comprising a rotatable barrel-type impeller, a housing for said impeller, a shield over said impeller, said shield having a cutting edge spaced apart from a wall of said housing, a baflle pivoted lengthwise along one edge thereof so the free baflle edge shall be movable towards or away from said cutting edge, an inlet for pulp directed substantially at right angles to and below the peripheral elements of the said impeller, and an outlet for tailings above said impeller.

3. An apparatus for circulating and distributing flotation pulp comprising a plurality, of barrel-type flotation machines spaced apart from each other transverse to the ax@s of the impellers thereof, a shield over each impeller, said shields having cutting edges, baflles pivoted lengthwise of and in pro ximity to said cutting edges, the free edges of said baflles movable towards and away from said cutting edges, feed inlets directed substantially tangential to, and at right angles to the peripheral elements of, the impellers, tailings outlets above the said impellers, and means for conducting liquid from each tailings outlet to any subsequent feed inlet.

4. An apparatus for circulating and distributing flotation pulp comprising a rotatable bar'rel-type impeller placed substantially horizontal, a housing defining an agitation chamber around sald impeller, a re stricted space defined longitudinally between said housing and said impeller, a shield over said impeller, said shield having a cutting edge, a bafiie pivoted along one edge thereof in proximity to said cuttin edge and above said restricted space, the co edge of said battle movable towards said cutting edge, an inlet for pulp located on the other side of said restricted space with reference to said .baflle, the said inlet being directed at substantially right angles to the peripheral elements of sald impeller; and an outlet for tailings on the other side, and near the other end, of said impeller. 1 4

5. An apparatus forcirculating and distributing flotation pulp, comprising a plufor tailings above said a 7. A rotatable impeller having staves of circular cross-section spaced apart clrcumrality of flotation machines having barreltype impellers spacedapart from one another transverse to the axes'of the impellers, shields having cuttin edges over said impellers, baffles pivote lengthwise of and in proximity to said cutting edges, the free edges of said baflles movable towards said cutting edges, a launder extending in the said transverse direction, feed inlets directed to points below said impellers substantially at right angles to the peripheral elements of the impellers, conductors extending from said launders to' said inlets, said conductors located in the space between successive machines after the first, and outlets leading from points above said impellers into said launders.

6. A rotatable impeller having staves of circular cross-section spaced apart circumferentially around the said impeller, a shield over said impeller, a cutting edge on .said shield, a pivoted bafile in operative imity to said cutting edge, a pulp inlet elow said shield, said pulp inlet being directed substantially at right angles to said staves and substantially tangent to the exterior circumference of said impeller, and an outlet shield.

ferentially around the said impeller, a shield having a-longitudinal cutting edge over said impeller andslightly spaced apart therefrom, said shield following substantially the curvature of the impeller, a housing having a wall spaced apart from the said longitudinal cutting edge, a baflle having a pivotal edge contiguous to said wall and a'free edge movable to substantially contact said shield adjacent said cutting edge, a pipe=directing a stream of pulp into said housing, said pipe being positioned in proximity to one end of said housing, said stream being transverse to said staves and substantially tangent to the circumference of said impeller, said stream beingfurther, below the horizontal hereto.

WILLIAM FAGERGREN.

.axial plane of said impeller; and an outlet 

